An academic at the University of Kansas has petitioned a judge to prevent his correspondence with his benefactors, foundations set up by the billionaire Koch brothers, from being made public under freedom of information laws.

Dr Arthur Hall, founder and director of the Center for Applied Economics at the university’s business school in Lawrence, Kansas is locked in a bitter fight with students who want to extract the documents as part of their exploration of potential conflicts of interest involving the Kochs. In alawsuit lodged with the district court of Douglas County, Hall argues that disclosure of the emails and letters would cause him “immediate and irreparable harm” and violate the principles of academic freedom.

For their part, the students say it is Charles and David Koch who are violating academic principles by using their vast wealth – the brothers own the second-largest private company in the US and are estimated to be worth more than $70bn – to inject their distinctive brand of conservatism into an independent seat of learning. Hall once worked as chief economist for Koch Industries’ lobbying arm, the Public Sector Group.

According to the KU group that is leading the freedom of information request, Students for a Sustainable Future, Hall’s center has received $1.4m in financial support from Koch foundations since it was set up in 2004.

A date has yet to be scheduled for a full hearing on the dispute. In the meantime, the Douglas County district court judge Robert Fairchild has placed a temporary block on the documents’ release pending his ruling.

The spat began in April when a group called Students for a Sustainable Future issued a request for documents under the state’s open records laws. That request covers all correspondence between Hall and a plethora of Koch entities including Koch Industries and charitable foundations in the name of both brothers over the hiring of the center’s staff and the ongoing funding of the center.

The university set a fee of $1,800 for retrieving the documents, which the students duly raised – $1,000 from the Kansas chapter of the American Association of University Professors and the rest from local donations. Earlier this month the university indicated that it had assembled the requested documents and was obliged to release them to the students under Kansas’ open records legislation – prompting Hall’s petition for an injunction.

Schuyler Kraus, a senior at the university who runs Students for a Sustainable Future, said the records request was designed to uphold academic integrity by ensuring there have been no conflicts of interest in the way Hall was hired or runs the center. “As an employee of a public institution, he should be fully accountable to students and the public, and these emails and documents should be fully available,” she said.

Hall confirmed to the Guardian that the Koch empire has been helping to cover his legal fees in bringing the lawsuit, and he called the Kochs themselves his “benefactors”. He said the students’ attempt to obtain the documents was an “invasive assault on my private freedom”.

Hall’s lawsuit says: “The disclosure of documents would have a widespread chilling effect on academic freedom within the academic community.”

This is not the first time that suspicions and allegations of conflict of interest have been raised in relation to the millions of dollars spent by the Koch brothers every year on university grants. In September, documents obtained by the Center for Public Integrity showed that the industrialists tried to impose “constraints” on Florida State University’s economics department in order to encourage teaching of radical market-oriented economics.

Through his work at the Center for Applied Economics, Hall has become a leading advocate of aggressive tax cutting in Kansas. He helped devise the platform of the state’s Republican governor Sam Brownback who has pushed through one of the most radical tax-slashing programs of any state in the country.

Hall acknowledged his basic economic beliefs were the same as the Kochs’: “We have an agreement that markets are powerful instruments of progress”, he said. But he denied his benefactors wielded any direct influence on his work. “There are no stipulations about anything I have to work on. I receive funding from them but I am free to choose my projects and to hire and fire as I see fit.”